This supplement to "Neighborhoods and Cardiovascular Risk in a Multiethnic Cohort" (R01 HL071759) will build on work carried out in the parent grant in order to improve the measures of neighborhood-level attributes to be examined in relation to cardiovascular outcomes. The measurement of neighborhood-level attributes remains a key challenge in the rapidly growing field of the investigation of neighborhood health effects. There is scant information on the reliability of different types of measures of neighborhood environments, and on the agreement between self-reported and objective measures. In addition, the use of multilevel techniques to develop improved measures of neighborhood-level constructs for small areas based on small numbers of observations in each area remains in its infancy. The objectives of this supplement are (1) To investigate the reliability of self-reported measures of neighborhood attributes (2). To investigate the agreement between GIS-based measures and self-reported measures of the neighborhood environment (3) To investigate the use of census data to improve empirical-Bayes estimates of neighborhood-level attributes using multilevel techniques; and (4) To evaluate the impact of alternate measurement and estimation strategies on estimates of neighborhood-health effects obtained from observational studies. The work to be carried out as part of this methodological supplement will be of direct relevance to the analyses planned under the parent grant by (1) quantifying the reliability of the measures used and (2) improving the estimates of neighborhood-level constricts to be used as predictors in models relating neighborhood-level factors to health outcomes in the MESA cohort. More generally, the work proposed will inform future studies that measure neighborhood-level attributes by providing estimates of the reliability and validity of neighborhood-level measures and by further developing the application of econometric techniques to the measurement of neighborhood-level constructs. [unreadable] [unreadable]